Holmium(III) sulfide
# Holmium(III) sulfide

Holmium(III) sulfide is the sulfide of holmium, with the chemical formula of $Ho_2S_3.$ Like other rare earth sulfides, it is used as a high-performance inorganic pigment.

## Preparation

Holmium(III) sulfide can be obtained by the reaction of holmium(III) oxide and hydrogen sulfide at 1325 °C.

    $Ho_2O_3$ + 3 $H_2S$ → $Ho_2S_3$ + 3 $H_2O$

## Properties

Holmium(III) sulfide has orange-yellow crystals in the monoclinic crystal system, with the space group $P2_1/m$ (No. 11). Under high pressure, holmium(III) sulfide can form in the cubic and orthorhombic crystal systems.

